Variation and Selection for Preharvest Seed Dormancy in Safflower1

Selection for preharvest seed dormancy had two aspects: selection for low or no germination in the head at maturity, followed by selection for short‐term seed dormancy as shown by high germination after a period of seed storage. No domestic safflower (Carthamus tinctorius L.) had 20% or less germination in the head; however, a high frequency of wild Carthamus species did. Short‐term dormancy was also found in wild species. Selections of Carthamus palaestinus Eig, which readily interbreed with domestic safflower, had as little as 7% germination with seeds stored for 3 weeks after harvest and as much as 100% with seeds stored for 19 weeks.